Garage door up-returner and circuit breaker

ABSTRACT

An Up-Returner for an obstructed downwardly moving overhead garage door; a Circuit Breaker, two-directional. I. At an operator for driving an overhead garage door open or closed; a door, moving downward toward closed position and encountering an obstruction, is automatically reversed in direction to fully reopen. II. Integral with the parts of assembly I, is a circuit breaker to shut off an overtime-running motor by breaking the electricsupply circuit, whether motor&#39;&#39;s direction of rotation is clockwise or counterclockwise. III. Improvements over prior designs.

United States Patent inventor Frederick A. Purdy 870 United Nations Plaza, New York, NY. 10017 Appl. No. 808,637

Filed Mar. 18, 1969 Patented July 6, 1971 Continuatlomiu-part o1 applicafion Ser. No. 401,264, Oct. 2, 1964, now Patent No. 3,444,344.

GARAGE DOOR UP-RETURNER AND CIRCUET BREAKER 13 Claims, 5 Drawing Figs.

US. Cl 49/28, 74/89.]5. 160/188,:518/266 Int. Cl E051 15/20, E05f 15/16 Field of Search 49/25, 26,

[56] References Cited UNlTED STATES PATENTS 2,951,460 9/1960 Pierson. 74/89.]5 X 3,248,630 4/1966 Purdy 7. 318/266 3,474,317 10/1969 Delaney 318/266 FOREIGN PATENTS 507,803 6/1939 Great Britain 49/28 Primary Examiner-J. Karl Bell AllmACT: An Up-Returner for an obstructed downwardly moving overhead garage door; a Circuit Breaker, twodirectional.

I. At an operator for driving an overhead garage door open or closed; a door, moving downward toward closed position and encountering an obstruction, is automatically reversed in direction to fully reopen.

ll. Integral with the parts of assembly 1, is a circuit breaker to shut off an overtime-running motor by breaking the electric-supply circuit, whether motors direction of rotation is clockwise or counterclockwise.

lll. Improvements over prior designs.

PATENIEIJ UL slsn 3,590 529 sum 1 BF 4 INVENTOR PATE NTED JUL 6 [an sum 2 or 4 INVENTOR PATENTEU JUL 6 19m fl T q 50/] LA z.

INVENTOR 3,590,529 sum 3 0F 4 PATENIED JUL 6 I97! sum um 4 K?) AZ? GARAGE DOOR UP-RETURNER AND CIRCUIT BREAKER RELATED APPLICATIONS BY PURDY PENDING Serial Flllng date Number Subiect matter October 2, 1964 401, 264 Reverslng switch, actuator. March 25, 1965 442, 731 Silver halide on door frame. January 18, 1968 698, 901 Circuit-breaker. September 26, 1968. 762,818 Safety-timer.

November 1,1968 veihlile unlocker for comblnation 0 Plvotally mounted gravity-timer,

. cont-impart 401,264 above. Motor operated door.

1 Number not known December 30 by attorney.

December 31, 1968 December 31, 1968....

OBJECTIVES For both Up-Retumer and Circuit Breaker, a Traveler" internally threaded for free-tuming within it by a threaded quill, locks automatically in emergencies to turn with quill and motor shaft.

At a door obstructed under drive in a downward door-closing movement, seizure by the traveler to lock onto motor shaft and to turn with it, is attended by a throw of connections to a reversing switch, causing the motor to change its direction of rotation and to return the door upward into open position, whereupon the motor-drive stops, pending the discovery and rectification of the obstruction.

At a motor overrunning for any reason in either direction, clockwise or counterclockwise, a traveler is drawn to lock onto the motor shaft and, moving within a short arc, to break off the supply 'of electric current, stopping the motor and preventing movement of the door, pending correction of the cause of overrun.

These are the main objectives of the invention. Other objectives willdevelop in the description.

DRAWINGS A preferred embodiment of the invention, and an alternative embodiment, are shown in the accompanying drawings, but the inventions are not limited to these embodiments and drawings.

FIG. 1 includes a sideward elevational view of that one of two guide-tracks, horizontal, curved, and vertical, which is at the rightward side of the garage as seen from a position midway of the doorway; and it includes a schematic outline of wiring for an electric circuit; and, partially, of a door in closed position and of a vehicle in position to actuate it.

FIG. 2 is a view in detail of essentials, including a door-drive motor and a cabinet of control-components mounted on the rear :end of the horizontal track as seen from the doorway in direction rearward of garage, parallel to the track.

FIG. 3'is a view on substantially the same scale as for FIG. 2, in a direction the same as for FIG. 1, with cover off cabinet disclosingdetail of essentials in a preferred embodiment of the invention:.

FIGS. 4 and 5 are views of motor-drive in the same direction as for FIGS. 1, and 3, showing essentials in two successive steps of an alternative embodiment of the invention.

DESCRIPTION It may be noted that-as appearing in FIG. 1 the drive of door is by a cable 27 in endless belt arrangement around driving sheave 26 and idling return pulley 15. Claim 7, herein, dependent from Claim 1, combines sheave 26 with novel features of Claim 1. This slip-grip-sheave has appeared in several of my earlier patents. It appears in detail as FIG. 15 of my copending application Ser. No. 401, 264, and is described on page 12 of that application. 7

In application Ser. No. 401,264, the detailed description covers a score of pages. To avoid repetition, except where essential or convenient herein, 1 take up here such advancesas are beyond the design in general of Ser. No. 401,264.

A quill 40, exteriorly left-hand threaded instead of the more usual right-hand, preferably 24 pitch, (24 spiral circlings to the inch) is keyed to the flat of motor shaft 25 so that it turns with the shaft.

A traveler 42 is internally left-hand threaded to match with the thread on quill 40, and to allow free turning within it by quill 40.

A conjunctive spring 46 connects, detachably by a persons fingers, at its upper-end eye, through the eye 47' of finger 47 that, in a fixture at factory, istightly force-fitted into a hole drilled radially in the perimeter of traveler 42. Conjunctive spring 46 reaches downward through a hole 20' in the horizontal top of cabinet 20 to connect by its lower-end eye through a hole 60 in a flange 60 that is formed horizontally from an upward extension of a trapeze 60, the two pendant sides of which trapeze are pivoted at 61 and 61 respectively, (FIG. 2). Conjunctive spring 46 keeps traveler 42 tending downward at its finger 47 while quill 40 turns within traveler 412-, also in the event of up-returning it holds a clevis 59 of the trapeze away from the exercise of its employment; normally to engage an arrestor appearing under the caption REVERSING- SWITCH, next to follow.

In that up-returning event, the holdoff of the trapeze, and the clevis with it, permits an unarrested and straight reversertongue to sweep upward, bringing reverser-head 54 to close the motor-circuit and set the door into its upward returning movement.

Towards the bottom ends of FIGS. 2 and 3, two flat members, hitch 22 and 22 appear, one on either surface, front and back, of bolster 21, and of trunk 23. Hitches 22 and 22 are pivoted on bolster 21 at 21, and on trunk at 23". These hitches have a tail-end 22 leftward (FIG. 3) of their pivot 21', hugging close to the surfaces of bolster and trunk. Except for the close contact by hitches with bolster, the lower end of trunk could stray or move out of line so far as to impair the precision by which silver-billets 50 and 50" make electrical contact with silver-terminals 62' and 63 on stationary termini 62 and 63. The trunk carries a sheet-metal limb, right-angle formed, (104 in Ser. No. 401,264) here indicated 23, (FIG. 3) by which a plastic block receptor 53 is supported; into which block reverser-tongue 50 is socketed.

Mounted closely outside the hitches are two toggle-springs and 71.

Shifters 31 and 32 are supported pivotally at leftward and rightward sides, FIG. 3, of'sheave 26 by respective pins 31' and 32'; these pins being riveted into, and extending from, hanger 19. When the door reaches the end of its opening movement, or the end of its closing movement, shifters 31 and 32 are thrown across by shipper-buttons 28 on upper strand 27, and 28" on lower strand 27", respectively, these shipperbuttons, designed as in FIG. 16 of Ser. No. 401,264, being adjustable into their proper positions along the cable, and wrench-locked onto cable.

Shifters 31 and 32 at their lower ends are interconnected by trace 29 to which they are pinned by free-turning rivets 29 and 29" used as pivots. Shifters 31 and 32 at their upper ends are interconnected pivotally at free-turning rivets 30' and 30" through the vertically disposed wing'of a right-angled pitman 30, the lower wing, horizontally disposed, having a hole 34, for access and engagement by a flexible arm 33 (wound as for an extension spring) which is force-fitted (not removable except by ripping) into a hole drilled radially into the perimeter of traveler 42.

. As appearing in FlG. 3, the horizontal wing of pitman 30 is cut away leftward of its hole 34, the cut taking away a shaving from the vertical wing. This cutaway avoids interference with bracket 49 on which are mounted circuit-breaker switches 86 and 87.

The dimension between pivot-holes in pitman 30 is the same as in trace 29.

Traveler 42, when confined by one or other of shoulders 43 and 44 on motor shaft 25, locks its threads against threads of quill 40, and must turn with quill and shaft.

An engagement of arm 33 with pitman 30 when quill 40, and traveler 42 locked to it, are turning clockwise of FlG. 3, throws top ends of shifters 31 and 32.rightward of FIG. 3 to reverse through trace 29, shift-spring 36, rocker 35, trunk 23, and reverser-parts) the direction of rotation of motor and sheave 26 to return the door upward away from an obstruction.

But this up-return occurs when a run of motor clockwise of FIG. 3 laboring with slippage of cable in slip-grip-sheave" 26, duelto an obstruction of door, or due to some other irregularity, draws traveler 42 rightward of FIG. 2 into position indicated D, out of its normal range to-and-fro between positions A and B.

In normal movements, to-and-fro between positions A and B, traveler 42 moves rightward of FIG 2 when the rotation of motor-shaft 25 and quill 40 is clockwise of FIG. 3, and it moves leftward of FIG. 2 when the rotation of motor shaft and quill is counterclockwise of FIG. 3. Within the normal extent of these movements to-and-fro, in relation to the number of revolutions of motor-shaft and sheave 26 in regular doordrives upward or downward, traveler 42 does not reach position C or position D" at either end of quill 40, and thus does not normally encounter either of the respective shoulders 43 or 44 of motor shaft 25.

Motor 24 is geared to 90 revolutions-per-minute. So motor shaft 25 turns 1% times per second-4 seconds to make 6 turns. Within a few seconds such as four, more or less, of motor-laboring upon a cable slipping in slip-grip-sheave," the traveler locks onto motor shaft 25.

Nine spiral-thread circlings of the thirty on a I la-inch length of quill may be regarded as assigned to normal to-and-fro movement midway of the quill. Traveler 42 has a thickness of one-quarter inch. The remainder of 7% threads or spiral circlings at each end of quill is the reserve of travel to be gone through before the'rotating quill may bring the traveler to one or other of the shoulders on motor shaft.

Shifters 31 and 32, brought into positions appearing as solid lines in FIG. 3, at the end of the door-opening movement, are held by shipper-button 28 and by inertia of the open door.

A mild resistance of 3% ounces at pitman 30 is partly attributable to relief from tension of one or other of the shiftsprings 36 and 37. Whenever button 28 or 28" respectively on upper or lower strand of cable is moved away from switcher 31 or 32, it frees the tension of the relieved shiftspring to bring the two shift-springs to rest under counter-opposition at a halfway adjustment stabilized by toggle springs 70 and 71.

REVERSlNG-SWITCH The reversing-switch is mentioned first among the objects of invention in application Ser. No. 401,264. There the subject is treated through pages 19 to 24 under caption REVERSER.

A more brief presentation may be offered here-a simple interpretation of the symbolic illustration of a reversing switch in the wiring-diagram toward lower left of FIG. 1..

Two wires reach down from a motor to four round terminals, two above and two below a pair of billets" appearing as rectangles. The billets are movable alternatively between upper and lower pairs of terminals. The wires crisscross diagonally from the upper pair to the lower pair. Positive flow of electric current from the leftward of the upper terminals may be encountered by the leftward of the billets when the billets make contacts upward, causing the motor to rotate counterclockwise to open a door. But when the billets are shifted downward, the rightward of the billets conveys the positive" to the opposite side of motor, causing the motor to rotate clockwise to close the door.

ln FIGS. 2 and 3 the upper terminus 62 and the lower terminus 63, of machinable insulating material supported on stand 66, each carries two rounded contact-heads of silver as 62 and 63' at its left and right corners respectively, and solderinglugs below the heads. Stems from the heads are pressfitted into the nylon or other material used. At each terminus the distance of separation of the two terminals 62 or 63' corresponds with the distance illustrated for billets 50 and 50" on reverser-head 54, FIG. 2, and complies with the requirement of the National Code as to separation of conductors of opposite polarities.

The support of each terminus 62 or 63 on stand 66 is by a single pivot-pin, respectively 64 and 65, free to rock in a hole through stand 66, the extent of rocking being within limits afforded by the stiffness of the wiring. Freedom thus to rock ensures that the silver-terminals will make equally positive contacts with respective silver-billets carried by the reverserhead.

To facilitate the disposition of conductor wires, or other means such as insulated conductive ribbons, in diagonally opposite directions from above left to below right, and vice versa, for the purpose of effecting a reversal of the direction of rotation by the motor, two soldering lugs are used as under contact-head 62'. One is for attachment of a conductor to or from the motor, the other is for the conductor that runs crisscross down along stand 66 to carry current of a polarity, such as positive,T which may have been reaching an electrode on a given side of the motor, over to the electrode on the opposite side.

Among improvements in group 111 under caption AB- STRACT OF THE DISCLOSURES a principal one is in the use of a tongue" of wire, wound as for an extension-spring, instead of the tongue of rubber described in Ser. No. 401,264.

1. One objective is reliability. The tongue is held in a bent shape by arrestor 53 through 24 hours of the day, except for a few seconds of infrequent entering and leaving the garage. Rubber, even pure gum rubber, tends, with time, to conform to the shape in which it is held the more. It becomes slow in making contacts by its billets with the stationary terminals when released from the arrestor. A spring of steel music wire goes into its normal straightness under full strength of tension in a flash of time, pressing and holding electrical contacts dependably.

2. Another objective is durability. Rubber will disintegrate in time; steel apparently never.

3. Another objective is economy. A steel spring, of a size for the use shown, may be had for a quarter of the price of a spread," as in Ser. No. 401,264, of pure gum rubber for the same purpose. I

4. Another object is simplicity in assembling. The three blocks, receptor 53', arrestor 53, and reverser-head 54, preferably of nylon, resilient but interminable in time of recovery, may be pressed into positions along the tongue by a fixture at factory, a fast operation compared with shaping and slitting of rubber.

5. Another object is protection of wiring. Two insulated wires may enter the interior tube-canal of the reverserspring 50 at the location of limb 23', and may emerge at a recess in reverser-head 54, thence may separate to connect into the respective silver-billets.

In FIG. 3 it will be observed that finger 47, conjunctive spring 46, the point to which spring 46 attaches on the upper end of trapeze lie in a straight line from the center of motor shaft to the center of the pivot 61 of trapeze. When traveler, on turning clockwise of FIG. 3, carries finger 47 leftward of this straight line, that part of trapeze 60 which reaches above trapeze-pivot .61 tends to bear to the left, and the part of trapeze below pivot 61 tends to the right. This affords the influence that holds trapeze or its clevis 59 from engagement with arrestor 53. It may be mentioned that when finger 437, at a counterclockwise turn is carried rightward of the straight line, it affords aid to the trapeze, rather than deterrence, to bring its clevis S9 or its seat 60" to engage under arrestor 53.

CIRCUIT BREAKER On bracket 49 two miniature electric switches 86 and 87 rated for I10 volts house-current are held so that the circuit breaker pushbutton stem (as 83) on each is one a level with the center of motor shaft 25. These are tyni switches" bought from Detroit-Controls Division of American Standard.

Through a break in the casing of switch 86, in FIG. 3, switch 87 appears, and the positions of casings of switches 86 and 87 are outlined by solid lines in FIG. 2. As observable in FIG. 3 these switches are not manufactured with the button 83 centered midway of the vertical length of their casings, but the button is centered in the width, FIG. 2. Each, then, is in register with the middle of traveler 42 and of its arm 33, or its finger 47, when the traveler reaches its extreme position indicated C or D, left and right, respectively, of FIG. 2. Position C corresponds to the limit of travelers range when reaching shoulder 43, FIG. 2, of motor shaft under a counterclockwise drive by motor and quill. Position D corresponds to the limit of travelers range when reaching shoulder 44 under a clockwise drive. Arm 33 and finger 47 are flexible, so that they can bend over button-point 83 until 83 is depressed.

The switches are wired in series so that a circuit breaking press of either button leftward of FIG. 3 by arm 33 turning counterclockwise of FIG. 3 on the left of FIG. 2, position C, or by finger 47 turning clockwise on the right of FIG. 2, position D, will stop the overrunning motor.

Thus an overrunning motor turning counterclockwise of FIG. 3 brings traveler 42 to lock onto quill 40 upon reaching shoulder 43; whereupon arm 33, moving with motor shaft, quill, and traveler, through about 60 of a circle, presses stem of button 83 of miniature switch 86, and thus opens the circuit of current-supply to stop the motor. A similar breaking of the circuit of an overrunning motor turning clockwise will occur as finger 47 moves with motor shaft, quill, and traveler, through approximately 105 of a circle.

Arm 33 has two uses: 1, to throw shifters 3K and 32 when moving clockwise for up-returning of door, and, 2, to break the circuit upon moving counterclockwise. Finger 47 has two: I, to hold trapeze clear of arrestor while arm 33 is throwing the shifters clockwise, and to break the circuit when itself moving clockwise.

Finger 47 does not reach button 83 during the throw of shifters 31 and 32 by arm 33 clockwise. In a clockwise movement it trails arm 33 by about 45 105 minus 60).

Hole 34 in pitman 30 is set leftward of midpoint. This ensures for arm 33 a good hold in hole 34, its top-end rising as it turns clockwise. In the counterclockwise direction, its top-end is already low and does not engage hole 34.

Finger 47 has a stiffness against sidewise resistance suitable to its need (as also does arm 33), in contrast to spring 46. The latter, wound as for an extension-spring, of small-gauge wire, is not overstrained in following the clockwise movement of finger 47, and, when recovering its normal length after such movement, it retains its control of traveler 42 from turning with thread-friction of rotating quill.

An overrun by motor can arise with a variety of conditions: an automobile passing through the doorway, plaster fallen from ceiling into horizontal track, a tool or ball lodging in the track, snow packed at sill, a rib on an opening or a closing door caught under or above the car's bumper, a garden-hose brought in to a faucet within the garage.

After the cause of the overrun has been found and rectified by the do-it-yourself home-owner following instructions in his manual, or by a serviceman, either button-head, as at 84, FIG. 3, is accessible, and may be pressed by ones finger to reset the switch and the circuit into closed condition.

OPERATION The following round of steps in door-closing and opening leads into automatic up-returning.

When door is being opened upward, the direction of rotation by motor is counterclockwise of FIG. 3, drawing the cable's upper strand 27 leftward on the groove at top of gripsheave 26. At termination of door-opening movement, shipperbutton 28 on upper-strand 27', throws the upper ends of shifters 311 and 32 leftward, away from broken line positions in FIG. 3 into positions indicated by solid lines. But the solidline position is not characteristic of an upward-moving door. When the door is moving upward the shifters are in the broken-line position. That is the position to be reached in this round of steps-returning an obstructed door upward.

In making the throw of shifters by shipper-button 28 into the solid line positions in FIG. 3 at the end of the opening movement of the door, trace 29 moved rightward of FIG. 3 while pitman 30 moved leftward. In that throw, trace 29 brought shift-spring 37 rightward and stretched it rightward toward the latter part of the throw. Spring 37 brought the top of rocker 35 rightward, which moved trunk 23 downward, and reverser-tongue 50 downward with it. Arrestor 53 came to rest on seat 60", so that reverser-tongue 50 yielded into a bend as appearing in FIG. 3, leaving a gap between two silver-billets 50: 50" on reverser-head 54 and two silver terminals 63', 63 on lower terminus 63. With that the door rests in open-position until pushbutton 58, or a gravitational fall of actuator 57, dislodges seat 60" from under arrestor 53, allowing reversertongue to straighten downward, bringing the lower ends of billets 50' and 50" into contact with the two terminals 63', 63, on lower terminus 63, causing motor 24, its shaft 25, and sheave 26 to rotate clockwise of FIG. 3. A clockwise rotation starts the door downward from open position toward closed position: sheave 26 pulls lower-strand 27" leftward of FIG. 1 around return-pulley I5 and rightward to detaching-lug 16 and lug-pin 17 to move the door downward by thrust through jointed-linkage (FIG. 11).

Upon the door reaching fully closed position, shipper-button 28" on lower-strand throws lower ends of shifters 32 and 3t leftward of FIG. 3, so that the upper ends move rightward, and the shifters arrive at their broken-lines position. In this leftward throw trace 29 will have drawn shift-spring 36 leftward and stretched it leftward in a f nal stage of the throw. Spring 36 will have drawn the top of rocker 3S leftward, moving trunk 23 upward, lifting reverser-tongue 50 upward and arrestor 53 upward to engage and stop at clevis 59 leaving a gap between silver-billets 50', 5t)", and silver terminals 62, 62 on upper terminus 62. The door remains in closed position pending dislodgement of clevis 59 from arrestor S3-to occur through pushbutton 58, or through a gravitational fall of actuator 57 by energization of solenoid to lift actuator when a headlamp beam of automobile is applied to and withdrawn from the cell of capsule on door-frame as appearing in Ser. No. 401,264. Upon billets and terminals coming into contact to close the circuit to the motor, the motor shaft 25, and sheave 26 will rotate counterclockwise of FIG. 3, bringing the door upward into open position.

Towards the beginning of this text, head of page 5, it is briefly observed that by holding trapeze 60 and its clevis 59 away from an engagement with arrestor 53 the reverser-tongue and its head 54 may sweep through to bring silver-billets 50' and 50" into immediate contact with silver-terminals 62 on upper terminus 62, and thus have an immediate up-returning of an obstructed door.

It has been observed towards the head of page 7 that the throw of shifters 31 and 32 into their broken-line positions is effected when a downwardly moving door is obstructed, causing traveler 42 to move to position D of FIG. 2. Arriving with traveler at position D, arm 33 lines up with hole 34 in pitman 30 in order to make the throw of shifters 31 and 32 from solidlines position over to broken line positions, the positions which, as noted at the beginning of this section captioned OPERATION, sets the rotation of motor 24 and sheave 26 counterclockwise, and up-returns the door.

It may be mentioned that after anup-return when top ends of shifters 31 and 32 are thrown by shipper-button 28 leftward of FIG. 3, causing a stoppage of motorby opening of the circuit by arrestor 53, the further flow of current to motor in due course is not suspended pending attention. The dooroperator may be used in all respects as if no obstruction had been encountered. But the sensible user will first look for the obstruction.

Total interruption of current to motor occurs at the circuit breaker.

A subassembly, designated 90 in FIGS. 2 and 3, represents a safety-timer Ser. No. 762,818 within tabulation on page 1 herein, not a part of this application.

ALTERNATIVE EMBODIMENT I An alternative embodiment of the up-retumer is shown in FIGS. 4 and 5. At FIG. 1 an extension spring 125 is inserted into the lower strand 27".of cable 27. Spring 125 has the strength needed (about l'pounds) to lift the door when the weight of door is properly counterbalanced. Spring 125 may be stretched by the drive of slip-grip sheave 26, in the event of door being obstructed. (Sheave 26 has a hub 26' and a flat as on motor shaft 25).

A follow arm 130, FIGS. 4 and 5, pivots at 131 on hanger I19. Riveted to the top end of follow-arm is an angle-piece 132 having a reach 133 towards the observer of FIGS. 4 and 5. Through this reach an aperture 134'is provided for traverse by the upper strand 27' of cable 27 but not admitting of passage by button 128 on cable 27. The lower left edge-corner of reach 133 stops against shifter 32 when the door is open, thus throwing shifter 32 leftward as in FIG. 4, instead of button 128' reaching shifter 32.

A follow-spring 129 is biased to apply a tendency in the follow-arm to move as far to the rightward of FIG. 4 as may be permitted by the condition obtaining in the upper strand 27 of door-drive cable. I To an upper corner ofreach I33 an extension spring 141 is attached; this as better seen in FIG. 5, being connected to a bead-chain or ball-chain 140 which is attached to the upper end of shifter 32. v

Spring 14] and chain 140 are of equal length so that they may hang downward as in FIG. 4 when shipper-button 128 moving with cable 27;.brought leftward of FIG. 4, brings reach 133 into contact with shifter 32.

I From the bottom end of follow-arm 130, a flange 130' extends toward the reader of FIG. 4. To this flange 130' there is attached an upper loop of a spring 146, which spring reaches downward through a hole 120 in the upper horizontal housing or roof of'cabinet, and is attached by its lower-eye to a flange 160' formed from top of trapeze 160 horizontally toward the reader of FIGS. 4 and 5. Spring 146 has the same purpose as noted for spring 46 in the preferred embodiment: that when a door under movement downward toward closed position meets an obstruction, and a reversal of the motor's polarity is effected through the reversing-switch as earlier observed under caption REVERSlNG-SWITCH" the full sweep by reverser-tcngue will occur without interference by arrestor 53.

OPERATION OF ALTERNATIVE EMBODIMENT imately parallel with the horizontal track to a return-pulley .15,

FIG. I, mounted at or near the doorway frame, thence over pulley l and leftward to weave through a detaching-lug 16 on pin 17 of jointed-linkage" 18 the lower of the. pins of which linkage connects to a bracket of the door-hardware. The lower-strand 27" of cable 27 in its rearward range carries a turnbuckle and the spring 125 first noted under this Alterntv fivn Fimhnriimanr" nnntinn When the-door is unde FmF/ement downward from its horizontal position to take its vertical closed position, the motor 24 is rotating clockwise as viewed in FIG. 1. In the clockwise rotation, the pull by motor shaft 25 andsheave 26 is rightward of FIG. 1 upon upper-strand 27 against pin 17 of the jointed-linkage, thence downward around return-pulley l5 and leftward, as lower-strand 27 through spring to sheave 26. The main rearward length of upper-strand 27' is under no tension in the pull to close the door, so it idles somewhat, the follow-spring 129 taking up the slack. When the door is obstructed in this downward drive into closed position, slip-grip sheave 26, under the continuing resistance by the obstruction; is forced to stretch spring 125 before sheave 26 resorts to slippage. Having the stretch of spring 125, sheave 26 pays off to the upper strand more cable-length than the normal of FIGS. 1 and'3. Follow-spring 129 immediately pills follow-arm 130 leftward of pivot 13], and, aided by oiliteroller 139, brings flange 130 on follow-arm, leftward, and bead-chain 140, and spring 141, into a rightward pull (FIG. 5) throwing upper ends of shifters 31 and 32 rightward of FIG. 5, thus effective through shift-spring 36 to pull the top of rocker 35 leftward, and to raise trunk 23 upward, and with it limb 23 and reverser-tongue upward without interference by arrestor 53 making an immediate closing of reversing-switch into a counterclockwise motor drive to bring'the door upward, away from the obstruction, and to rest in open position.

What I claim is:

I. In a door-operator, a door, a reversiblemotor and drive shaft, connections between said motor and said door for driving said door in a direction toward opening of door, and for driving said door in a direction for closing of door, a threaded quill keyed to said shaft, a threaded traveler matched to the thread of said quill, for moving to-and-fro lengthwise of said quill, shoulders on said shaft, one at each end of said quill, for confining said quill, and for affording a limit to movement of said traveler at each end of said quill, and for locking together said threads of quill and traveler when said traveler reaches either limit; for causing said locked traveler and quill to move in unison with said motor shaft in an are for up-returning and circuit breaking; an arm extending radially from the perimeter of said traveler, shifters sidewise of said motor drive shaft connections between said arm and said shifters for throwing said shifters clockwise, connections between said shifters and a reversing switch for obtaining in said clockwise throw a direction of rotation at said motor for producing an upward door-opening drive, for returning into open position an obstructed downward-movingdoor.

2. The combination of claim 1 with a finger extending radially from the perimeter of said traveler, connections between said finger and an arresting trapeze for immobilizing said trapeze in concert with said clockwise throw of said shifters.

3. The combination of claim 2 with a circuit breaker comprising dual electric switches, one said switch with a circuitopening pushbutton in the path of said arm moving counterclockwise, the other said switch with a circuit-opening pushbutton in the path of said finger moving clockwise.

4. The combination of claim 3 with exposed pushbuttons pressed by a person's finger for restoring to current-carrying condition said circuit opened by said arm or by said finger.

5. The combination of claim 2 with an arm extending radially from said traveler, for moving clockwise in up-returning and for moving counterclockwise in circuit breaking; and with a finger for moving clockwise in immobilizing said trapeze in up-returning and for moving further clockwise in circuit breaking.

6. In a door-operator, a door, a reversible motor with a drive shaft and a sheave for driving an endless belt, connections between said belt and said door for driving said door in a direction toward opening of said door, and for driving said door in a direction toward closing of said door, a circuit for conducting electric current to and from said motor, a switch in the circuit for controlling the directions of movement of said door, said switch including two stationary termini, each terpolarities, said switch including also a tongue movable from one tenninus to the other and bearing two current-conducting;

billets arranged to make circuit-closing electrical contacts with said terminals at one of said termini for causing at said ing at said motor a direction of rotation to drive said door in said downward direction when said billets on said tongue make contact with said terminals on said other terminus, said tongue being of wire wound in spiral circlings tensioned to press circling-to-circling as in an extension-spring 7. The combination of claim 6 with a series of essential parts of suitable material fitted onto said wire-wound tongue.

8. The combination of claim 6 in which said billet-carrying arrangement includes a recess in which two electricity conducting wires brought through the tube-canal of said tongue make connection with said electrically conducting billets.

9. The combination of claim 6 in which each of said two termini pivots freely on a supporting stand.

10. In a door operator, a'door, a reversible motor with doordrive connections for driving said door in an upward direction towards open position and in an opposite downward direction towards closed position; a circuit for conveying electric current to and from said motor, a switch in said circuit arranged for conducting said current to said motor in a polarity essential to an alternative order of succession (opening-closing opening-closing) for causing rotation of said motor in a counterclockwise direction for door-opening, and for causing rotation of said motor in a clockwise direction for door-closing; said switch including a tongue wound cylindrically from suitable wire in spiral circlings as for an extension-spring, said tongue bearing current-carrying conductors for energizing said motor, means for breaking said circuit and stopping said motor; arresting means for holding said tongue and said currentcarrying conductors short of making circuit-closing contacts, means for dislodging said arresting means, signalling means for activating said dislodging means, and means for restoring said breaking of said circuit, and for re-energizing said motor with current of said polarity for rotating said motor in one of said directions for effecting door-movement according to said alternative order of succession.

ll. In a door-operator, a door, a reversible motor having a drive shaft and a sheave with a groove around the periphery of said sheave, for driving an endless belt, said belt having an upper strand at an upper side of passage into and out of said groove, and having a lower strand at a lower side of passage into and out of said groove, connections between said belt and said door for driving said door in an upward direction toward opening said door, and for driving said door in a downward direction toward closing said door; an electric supply circuit to said motor, a reversing switch in said circuit, said switch having a tongue for making conductor contacts for alternating the polarity of electric current to said motor for driving said door in said upward direction, and alternatively in said downward direction; shifters and connections between said sheave and said switch for alternatively throwing said tongue; and upper shipper-button adjustable in its position lengthwise of said upper strand and locked onto said upper strand of said belt, and a lower shipper-button adjustable in its position lengthwise of said lower strand and locked into position on said lower strand, for governing said alternative throwing of said tongue; a follow-arm, and a follow-spring, biased to bear upon slack in said upper strand; stretchable means within said lower strand for yielding, to the drive of said sheave, a length of said lower strand in event of an obstructed downward moving door, and for transfering said length into a slack in said upper strand for accommodating to follow-pressure of said follow-arm and for drawing said shifters to throw said tongue into making said door-opening conductor contacts for causing said obstructed door to return upward into said open position.

12. The combination of claim 11 with said tongue wound cylindrically of wire in spiral circlings tensioned to press circlin -to-circlin as in an extension-s rin Ii The com ination of claim 1 with essential operative parts mounted onto the periphery of said tongue. 

1. In a door-operator, a door, a reversible motor and drive shaft, connections between said motor and said door for driving said door in a direction toward opening of door, and for driving said door in a direction for closing of door, a threaded quill keyed to said shaft, a threaded traveler matched to the thread of said quill, for moving to-and-fro lengthwise of said quill, shoulders on said shaft, one at each end of said quill, for confining said quill, and for affording a limit to movement of said traveler at each end of said quill, and for locking together said threads of quill and traveler when said traveler reaches either limit; for causing said locked traveler and quill to move in unison with said motor shaft in an arc for up-returning and circuit breaking; an arm extending radially from the perimeter of said traveler, shifters sidewise of said motor drive shaft connections between said arm and said shifters for throwing said shifters clockwise, connections between Said shifters and a reversing switch for obtaining in said clockwise throw a direction of rotation at said motor for producing an upward dooropening drive, for returning into open position an obstructed downward-moving door.
 2. The combination of claim 1 with a finger extending radially from the perimeter of said traveler, connections between said finger and an arresting trapeze for immobilizing said trapeze in concert with said clockwise throw of said shifters.
 3. The combination of claim 2 with a circuit breaker comprising dual electric switches, one said switch with a circuit-opening pushbutton in the path of said arm moving counterclockwise, the other said switch with a circuit-opening pushbutton in the path of said finger moving clockwise.
 4. The combination of claim 3 with exposed pushbuttons pressed by a person''s finger for restoring to current-carrying condition said circuit opened by said arm or by said finger.
 5. The combination of claim 2 with an arm extending radially from said traveler, for moving clockwise in up-returning and for moving counterclockwise in circuit breaking; and with a finger for moving clockwise in immobilizing said trapeze in up-returning and for moving further clockwise in circuit breaking.
 6. In a door-operator, a door, a reversible motor with a drive shaft and a sheave for driving an endless belt, connections between said belt and said door for driving said door in a direction toward opening of said door, and for driving said door in a direction toward closing of said door, a circuit for conducting electric current to and from said motor, a switch in the circuit for controlling the directions of movement of said door, said switch including two stationary termini, each terminus holding two current-conducting terminals of opposite polarities, said switch including also a tongue movable from one terminus to the other and bearing two current-conducting billets arranged to make circuit-closing electrical contacts with said terminals at one of said termini for causing at said motor a direction of rotation to drive said door in said upward direction, and arranged to make circuit-closing electrical contacts with said terminals at the other of said termini for causing at said motor a direction of rotation to drive said door in said downward direction when said billets on said tongue make contact with said terminals on said other terminus, said tongue being of wire wound in spiral circlings tensioned to press circling-to-circling as in an extension-spring.
 7. The combination of claim 6 with a series of essential parts of suitable material fitted onto said wire-wound tongue.
 8. The combination of claim 6 in which said billet-carrying arrangement includes a recess in which two electricity conducting wires brought through the tube-canal of said tongue make connection with said electrically conducting billets.
 9. The combination of claim 6 in which each of said two termini pivots freely on a supporting stand.
 10. In a door operator, a door, a reversible motor with door-drive connections for driving said door in an upward direction towards open position and in an opposite downward direction towards closed position; a circuit for conveying electric current to and from said motor, a switch in said circuit arranged for conducting said current to said motor in a polarity essential to an alternative order of succession (opening-closing opening-closing) for causing rotation of said motor in a counterclockwise direction for door-opening, and for causing rotation of said motor in a clockwise direction for door-closing; said switch including a tongue wound cylindrically from suitable wire in spiral circlings as for an extension-spring, said tongue bearing current-carrying conductors for energizing said motor, means for breaking said circuit and stopping said motor; arresting means for holding said tongue and said current-carrying conductors short of making circuit-closing contacts, means for dislodging said arresting means, signalling means for activating said dislodging means, and means for restoring said breaking of said circuit, and for re-energizing said motor with current of said polarity for rotating said motor in one of said directions for effecting door-movement according to said alternative order of succession.
 11. In a door-operator, a door, a reversible motor having a drive shaft and a sheave with a groove around the periphery of said sheave, for driving an endless belt, said belt having an upper strand at an upper side of passage into and out of said groove, and having a lower strand at a lower side of passage into and out of said groove, connections between said belt and said door for driving said door in an upward direction toward opening said door, and for driving said door in a downward direction toward closing said door; an electric supply circuit to said motor, a reversing switch in said circuit, said switch having a tongue for making conductor contacts for alternating the polarity of electric current to said motor for driving said door in said upward direction, and alternatively in said downward direction; shifters and connections between said sheave and said switch for alternatively throwing said tongue; and upper shipper-button adjustable in its position lengthwise of said upper strand and locked onto said upper strand of said belt, and a lower shipper-button adjustable in its position lengthwise of said lower strand and locked into position on said lower strand, for governing said alternative throwing of said tongue; a follow-arm, and a follow-spring, biased to bear upon slack in said upper strand; stretchable means within said lower strand for yielding, to the drive of said sheave, a length of said lower strand in event of an obstructed downward moving door, and for transfering said length into a slack in said upper strand for accommodating to follow-pressure of said follow-arm and for drawing said shifters to throw said tongue into making said door-opening conductor contacts for causing said obstructed door to return upward into said open position.
 12. The combination of claim 11 with said tongue wound cylindrically of wire in spiral circlings tensioned to press circling-to-circling as in an extension-spring.
 13. The combination of claim 11 with essential operative parts mounted onto the periphery of said tongue. 